path: root/arch/arm/mach-s3c2410/dma.c

/* linux/arch/arm/mach-bast/dma.c
 *
 * (c) 2003-2005 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C2410 DMA core
 *
 * http://www.simtec.co.uk/products/EB2410ITX/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Changelog:
 *  27-Feb-2005 BJD  Added kmem cache for dma descriptors
 *  18-Nov-2004 BJD  Removed error for loading onto stopped channel
 *  10-Nov-2004 BJD  Ensure all external symbols exported for modules
 *  10-Nov-2004 BJD  Use sys_device and sysdev_class for power management
 *  08-Aug-2004 BJD  Apply rmk's suggestions
 *  21-Jul-2004 BJD  Ported to linux 2.6
 *  12-Jul-2004 BJD  Finished re-write and change of API
 *  06-Jul-2004 BJD  Rewrote dma code to try and cope with various problems
 *  23-May-2003 BJD  Created file
 *  19-Aug-2003 BJD  Cleanup, header fix, added URL
 *
 * This file is based on the Sangwook Lee/Samsung patches, re-written due
 * to various ommisions from the code (such as flexible dma configuration)
 * for use with the BAST system board.
 *
 * The re-write is pretty much complete, and should be good enough for any
 * possible DMA function
 */

#include <linux/config.h>

#ifdef CONFIG_S3C2410_DMA_DEBUG
#define DEBUG
#endif

#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/sysdev.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/delay.h>

#include <asm/system.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/dma.h>

#include <asm/mach/dma.h>
#include <asm/arch/map.h>

/* io map for dma */
static void __iomem *dma_base;
static kmem_cache_t *dma_kmem;

/* dma channel state information */
s3c2410_dma_chan_t s3c2410_chans[S3C2410_DMA_CHANNELS];

/* debugging functions */

#define BUF_MAGIC (0xcafebabe)

#define dmawarn(fmt...) printk(KERN_DEBUG fmt)

#define dma_regaddr(chan, reg) ((chan)->regs + (reg))

#if 1
#define dma_wrreg(chan, reg, val) writel((val), (chan)->regs + (reg))
#else
static inline void
dma_wrreg(s3c2410_dma_chan_t *chan, int reg, unsigned long val)
{
	pr_debug("writing %08x to register %08x\n",(unsigned int)val,reg);
	writel(val, dma_regaddr(chan, reg));
}

#endif

#define dma_rdreg(chan, reg) readl((chan)->regs + (reg))

/* captured register state for debug */

struct s3c2410_dma_regstate {
	unsigned long         dcsrc;
	unsigned long         disrc;
	unsigned long         dstat;
	unsigned long         dcon;
	unsigned long         dmsktrig;
};

#ifdef CONFIG_S3C2410_DMA_DEBUG

/* dmadbg_showregs
 *
 * simple debug routine to print the current state of the dma registers
*/

static void
dmadbg_capture(s3c2410_dma_chan_t *chan, struct s3c2410_dma_regstate *regs)
{
	regs->dcsrc    = dma_rdreg(chan, S3C2410_DMA_DCSRC);
	regs->disrc    = dma_rdreg(chan, S3C2410_DMA_DISRC);
	regs->dstat    = dma_rdreg(chan, S3C2410_DMA_DSTAT);
	regs->dcon     = dma_rdreg(chan, S3C2410_DMA_DCON);
	regs->dmsktrig = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
}

static void
dmadbg_showregs(const char *fname, int line, s3c2410_dma_chan_t *chan,
		 struct s3c2410_dma_regstate *regs)
{
	printk(KERN_DEBUG "dma%d: %s:%d: DCSRC=%08lx, DISRC=%08lx, DSTAT=%08lx DMT=%02lx, DCON=%08lx\n",
	       chan->number, fname, line,
	       regs->dcsrc, regs->disrc, regs->dstat, regs->dmsktrig,
	       regs->dcon);
}

static void
dmadbg_showchan(const char *fname, int line, s3c2410_dma_chan_t *chan)
{
	struct s3c2410_dma_regstate state;

	dmadbg_capture(chan, &state);

	printk(KERN_DEBUG "dma%d: %s:%d: ls=%d, cur=%p, %p %p\n",
	       chan->number, fname, line, chan->load_state,
	       chan->curr, chan->next, chan->end);

	dmadbg_showregs(fname, line, chan